Presettable subtracting counter

ABSTRACT

A digit wheel is adapted to be preset to a preset position corresponding to a count higher than zero and to perform a rotational subtracting movement from said preset position to and beyond a position corresponding to a zero count. A cutoff pinion is operatively connected to said digit wheel and arranged to rotate to a signaling position in response to a subtracting movement of said digit wheel beyond said position corresponding to a zero count. A signaling lever is movable between a signaling position and a non-signaling position. Biasing means resiliently urge said signaling lever to said non-signaling position. A signal generator is under control of said lever and arranged to generate a signal when, and only when, said lever is in said signaling position. Cam means are connected to said pinion for rotation therewith and in direct engagement with said lever and arranged to permit said lever to assume its non-signaling position when said pinion is in a position other than its signaling position and to move said lever to its signaling position in response to a rotation of said pinion to its signaling position.

United States Patent 1 Pfeiffer Y PRESETTABLE SUBTRACT ING COUNTER [75]Inventor: Horst Pfeifier, Aldingen Kreis Tut tlingen, Germany [73]Assignee: Firma J. Hengstler K.G., Aldingen Kreis Tuttlingen, Germany,

[22] Filed: Dec. 18, 1972 [21] Appl. No.: 316,287

[30] Foreign Application Priority Data July 22, 1972 Germany P 22 36098.1

[52] US. CL... ...235/132 R, 235/132 E [51] Int. Cl. G06f 15/18 [58]Field of Search 235/132 R, 132 E,

- 235/132 A,6l PA [56] References Cited UNITED STATES PATENTS 2,479,4828/1949 Edler 235/132 R 2,900,133 8/1959 Durand 235/132 R 3,231,1901/1966 Wollar r 235/132 E 3.343.789 9/1967 Wales, Jr. et a1, 235/132 R 1Jan. 15, 1974 Primary Examiner-Stephen J. Tomsky Attorney-George F.Dvorak et al.

[57] ABSTRACT A digit wheel is adapted to be preset to a preset positioncorresponding to a count higher than zero and to perform a rotationalsubtracting movementfrom said preset position to and beyond a positioncorresponding to a zero count. A cutoff pinion is operatively connectedto said digit wheel and arranged to rotate to a signaling position inresponse to a subtracting movement of said digit wheel beyond saidposition corresponding to a zero count. A signaling lever is movablebetween a signaling position and a non-signaling position. Biasing meansresiliently urge said signaling lever to said non-signaling position. Asignal generator is under control of said lever and arranged to generatea signal when, and only when, said lever is in said signaling position.Cam means are connected to said pinion for rotation therewith and indirect engagement with said lever and arranged to permit said lever toassume its non-signaling position when said pinion is in a positionother than its signaling position and to move said lever to itssignaling position in response to a rotation of said pinion to itssignaling position.

-11 Claims, 5 Drawing Figures PATENTEU 1 5974 3. 786,240

SHEET 1 OF 3 Fig.7

Fig.2

tates the cut-off pinion during the subtracting movement of the highorder position wheel. from zero to nine. In this operation, only smalltorques can be overcome so that this rotational movement can be usedonly to release pawls. Two different arrangements and modes of operationof these pawls are known. In the first embodiment, the pawl isspring-biased by the cutoff lever and bears on the pinion at itsaddendum circle I whereas the pawl is released as the pinion rotates.For this purpose, the cut-off pinion has four teeth so that a rotationthrough 90 will result in a release and reengagement of the pawl. Toprovide this four-tooth design, four of the eight existing teeth aremilled off in the range of the pawl. In the other embodiment, thecut-off pinion is similarly designed and the pawl protrudes into thegaps between the teeth of the cut-off pinion so that a cut-off rotationof the cut-off pinion will lift off the pawl to release the cut-offlever. In both embodiments, the spring-loaded cut-off lever is set andthen locked by the pawl when the counter is reset to zero. These knowndesigns have the disadvantage that they can be used only to release apawl and'are sensitive to shakes. Besides, a continuous signal cannot begenerated without a pawl and cut-off lever so that these designs areexpensive and yet unreliable.

It is an object of the presentinvention to eliminate these disadvantagesin an arrangement which is both simple and compact. In the presettablecounting mechanism for subtracting counters, which mechanism comprises acut-off pinion which is associated with the high order position wheeland adapted to generate a signal in response to a subtracting movementfrom the zero position, this object is accomplished in that the cut-offpinion comprises one or more cams for directly operating a signalinglever, which is spring-biased and generates a signal, which ismaintained until the counter is reset, and the number of cams on thecut-off pinion equals one-fourth of the number of teeth of eachswitching pinion.

Specifically, the cut-off cam or cams operatively connected to the highorder position wheel has or have together two stable positions relativeto the signaling lever. These are the non-signaling position and thesignaling position. Each cut-off cam has a nose, which in the signalingposition of the cam is adapted to enter a groove in the signaling leverand to engage a stop in the lever when the pinion is moved bodily awayfrom. the high order position wheel. The signaling lever is rotatablymounted on the digit wheel shaft and when pivotally moved out of itsnormal position initiates the generation of a signal by means of aswitch finger, which for this purpose acts on a spring-biasedpush-button for controlling a switch. For resetting, the cut-off pinionshaft carrying the cut-off pinion is bodily movedv away from the highorder position wheel. This causes the cam of the cut-off pinion toreturn to its initial position because the cam engages the groove in thesignaling lever.

With reference to the drawings, an embodiment of the presettablecounting mechanism arranged to generate a signal by means of a cut-offpinion, in accordance with the invention, will now be explained.

FIG. 1 shows the signaling mechanism in its initial position.

FIG. 2 shows the signaling mechanism in a position assumed in responseto a rotation of the high order position wheel 1 from position 0 toposition 9.

FIG. 3 illustrates how the resetting operation results in theelimination of the signal which has been continued after it has beeninitiated.

Finally, FIG. 4 shows the position assumed when the counter has beenreset.

FIG. 5 is a top plan view showing the mechanism.

With reference to FIG. 1, a high order position wheel 1 is rotatablymounted on a shaft 2 and provided with two switching teeth 3 and a rim4. The wheel I is shown in FIG. 1 in a positioncorresponding to thedigit0. The high order position wheel 1 is in mesh with a cutoff pinion5, which is provided with a'diametral double cam 6 and by means of ashaft 7 is rotatably mounted in a bridge 8. A signaling lever 9 ispivotally mounted on the shaft 2 and by-a spring loaded pushbutton ll ofa switch 12 is resiliently urged against the double cam 6 and tends tomove the latter to a horizontal position.

For the resetting operation, illustrated in FIG. 3, the I signal whichhas been maintained after it has been initiated,.is eliminated. By meansof the bridge 8, an outward pivotal movement is imparted to the cut-offpinion shaft 7 so that the double cam 6 is tilted out of its signalingposition and the signal generated by the switch 12 is eliminated. v

A nose 6a is associated with the double cam 6 of the cut-off pinion 5and cooperates with the stopg'roove 9a of the signaling lever so as toimpart a rotation to the cut-off pinion 5 during the outward pivotalmovement of the cut-off pinion shaft 7. 1

FIG. 4 shows the position which will be assumed when the high orderposition wheel has been reset, for instance, to position 2 and thedouble cam 6 on the cut-off pinion 5 has returned to its initialposition.

FIG. 5 shows the wheel 1, the shaft 2 on which the wheels 1 are mounted,and the signaling lever 9, as well as the cut-off pinion shaft 7, whichis parallel to the shaft 2 and carries the cut-off pinion 5, cam 6 andnose 6a. The shaft 7 also carries a nonnal carry pinion 13, which inknown manner serves for the decimal carry from the next lower orderposition wheel 14 to the high order position wheel 1.

What is claimed is:

l. A presettable subtracting counter, which comprises a digit wheel,which is adapted to be preset to a preset position corresponding to acount higher than zero and to perform a rotational subtracting movementfrom said preset position to and beyond a position corresponding to azero count,

a cut-off pinion which is operatively connected to said digit wheel andarranged to rotate to a signaling position in response to a subtractingmovement of said digit wheel beyond said position corresponding to azero count,

a signaling lever movable between a signaling position and anon-signaling position,

biasing means resiliently urging said signaling lever to saidsignalingposition,

a signal generator which is under control of said lever and arranged togenerate a signal when, and only when, said lever is in said signalingposition, and

cam means connected to said pinion for rotation therewith and in directengagement with said lever and arranged to permit said lever to assumeits nonsignaling position when said pinion is in a position other thanits signaling position and to move said lever to its signaling positionin response to a rota tion of said pinion to its signaling position.

2. A counter as set forth in claim 1', in which said digit wheel is ahigh order position digit wheel.

3. A counter as set forth in claim 2, in .which a carry pinion isprovided, which is operable to initiate an angular step of said digitwheel and which has teeth in'a number which is an integral multiple offour, and

said cam means comprise cams in a number which is equal to one-fourth ofsaid numberof teeth.

4. A counter as set forth in claim 3, in which said carry pinion haseight teeth and said cam means comprise two cams.

5. A counter as set forth in claim 1, in which said cam means comprise aplurality of cams, each of which is engageable with said lever.

6. A counter as set forth in claim 1, in which said pinion is rotatableto two stable positions, one of which is said signaling position of saidpinion.

0 asing means comprise a spring-loaded push-button operativelyinterposed between said lever and said signal generator.

9. A counter as set forth in claim 1, in which said pinion is bodilymovableaway from said digit wheel to an inoperative position,

said lever is provided with stop means facing said cam means, and

said cam means are arranged to engage said stop means when said pinionis in said signaling position and is moved to an inoperative position.

10. A counter as set forth in claim 9, in which said pinion is rotatableto two stable angular positions, one of which is said signaling positionof said pinion, and

said cam means are arranged to rotate said pinion to the other of itsstable'positions in response to a bodily movement of said'pinion to saidinoperative position when said pinion is initially in said signalingposition.

11. A counter as set forth in claim 9, in which said lever is formedwith a recess which is defined by said stop means and said cam meanscomprise a nose arranged to engage said lever in said recess when saidpinion is in its signaling position.

1. A presettable subtracting counter, which comprises a digit wheel,which is adapted to be preset to a preset position corresponding to acount higher than zero and to perform a rotational subtracting movementfrom said preset position to and beyond a position corresponding to azero count, a cut-off pinion which is operatively connected to saiddigit wheel and arranged to rotate to a signaling position in responseto a subtracting movement of said digit wheel beyond said positioncorresponding to a zero count, a signaling lever movable between asignaling position and a non-signaling position, biasing meansresiliently urging said signaling lever to said signaling position, asignal generator which is under control of said lever and arranged togenerate a signal when, and only when, said lever is in said signalingposition, and cam means connected to said pinion for rotation therewithand in direct engagement with said lever and arranged to permit saidlever to assume its non-signaling position when said pinion is in aposition other than its signaling position and to move said lever to itssignaling position in response to a rotation of said pinion to itssignaling position.
 2. A counter as set forth in claim 1, in which saiddigit wheel is a high order position digit wheel.
 3. A counter as setforth in claim 2, in which a carry pinion is provided, which is operableto initiate an angular step of said digit wheel and which has teeth in anumber which is an integral multiple of four, and said cam meanscomprise cams in a number which is equal to one-fourth of said number ofteeth.
 4. A counter as set forth in claim 3, in which said carry pinionhas eight teeth and said cam means comprise two cams.
 5. A counter asset forth in claim 1, in which said cam means comprise a plurality ofcams, each of which is engageable with said lever.
 6. A counter as setforth in claim 1, in which said pinion is rotatable to two stablepositions, one of which is said signaling position of said pinion.
 7. Acounter as set forth in claim 1, which comprises a digit wheel shaft, onwhich said digit wheel and said lever are independently rotatablymounted, and an operating finger, which is rigid with said lever andcooperates with said signal generator.
 8. A counter as set forth inclaim 1, in which said biasing means comprise a spring-loadedpush-button operatively interposed between said lever and said signalgenerator.
 9. A counter as set forth in claim 1, in which said pinion isbodily movable away from said digit wheel to an inoperative position,said lever is provided with stop means facing said cam means, and saidcam means are arranged to engage said stop means when said pinion is insaid signaling position and is moved to an inoperative position.
 10. Acounter as set forth in claim 9, in which said pinion is rotatable totwo stable angular positions, one of which is said signaling position ofsaid pinion, and said cam means are arranged to rotate said pinion tothe other of its stable positions in response to a bodily movement ofsaid pinion to said inoperative position when said pinion is initiallyin said signaling position.
 11. A counter as set forth in claim 9, inwhich said lever is formed with a recess which is defined by said stopmeans and said cam means comprise a nose arranged to engage said leverin said recess when said pinion is in its signaling position.